1, how to accurately retain urine specimens Accurate retention of urine specimens is important to obtain an accurate diagnosis. Only if the collection method is appropriate, the test results will have diagnostic value. The most important thing is to avoid contamination. In the examination of urine specimens from female patients, if the presence of pus cells is found without paying attention to the correct method of urine collection, it may be due to the contamination of vaginal secretions. Therefore, when collecting urine specimens from female patients, the vulva and the external urethra should be cleaned first, the labia majora need to be separated when urinating, and the primary urine should be discarded, and then the middle urine should be retained and sent for examination. Male patients with prepuce and glansitis may also contaminate the urine specimen, so they should also wash the urethral orifice and collect the middle urine after removing the primary urine for examination. In addition, the utensil holding the urine specimen should be relatively clean. In infants and young children, urine specimens are usually obtained by fixing a sterile bag to the external genitalia of the child, although it is often difficult to distinguish whether this is due to urethral infection or contamination. Therefore, the best way to avoid contamination of the specimen is to obtain urine by suprapubic puncture of the bladder, with careful disinfection of the skin during the puncture to avoid contamination of the specimen and bladder infection. The best specimen to retain is a fresh specimen sent in time for examination. If the specimen is left at room temperature for too long, the bacteria will grow too fast, the pH value of the urine will change, and the cellular pattern will be broken down, which will affect the accuracy of the test. If it is true that the specimen cannot be sent for testing immediately, it should be placed in a refrigerator at 5ºdegrees for cold storage. In special cases, when a 24-hour specimen needs to be retained, a preservative should be added to the urine specimen. 2, What is proteinuria The normal kidney filtration system is able to retain large molecules so that they are not lost, including various large protein molecules. However, in some disease conditions, when the kidney filtration system is damaged, or when there are abnormal changes in the charge, or abnormal changes in hemodynamics, etc., this can lead to abnormal loss of protein from the urine. Under normal circumstances, the amount of protein lost in the urine should be less than 150 mg day and night, and the qualitative examination should be negative. If the amount of protein excreted in 24 hours exceeds 1 gram, it should be considered abnormal and defined as proteinuria, and the qualitative protein test should be positive at this time. 3.What are the pathological types of proteinuria Proteinuria can be the early manifestation of renal vascular, glomerular or tubulointerstitial nephropathy. There are many different causes of proteinuria, and if they can be carefully distinguished, they can often provide a reliable and important basis for the diagnosis of kidney disease. In clinical practice, proteinuria is generally classified into five categories according to its etiology. These are tubular proteinuria, glomerular proteinuria, overflow proteinuria, secretory proteinuria and tissue proteinuria. The most common type of proteinuria is mostly glomerular, i.e., caused by damage to the glomerular filtration membrane lesion, resulting in increased permeability to protein. The protein component of glomerular proteinuria is usually mainly albumin, and if the lesion is severe there may also be a loss of larger molecular weight protein components such as globulin. In general, glomerular disease should be suspected if the total amount of 24-hour urine protein exceeds 1 gram, and the diagnosis is confirmed when the total amount of protein is greater than 2 grams. When various renal tubular diseases lead to impaired tubular reabsorption of protein, the proteinuria is called tubular proteinuria. In this case, most of the protein is lost in small and medium-sized molecules (such as β2 microglobulin). Because of the low molecular weight of these proteins, the urine protein quantification in these patients is usually not high, usually not exceeding 2 grams. Renal tubular proteinuria is often accompanied by other associated dysfunctions of the proximal tubule and clinically presents with abnormal symptoms such as glycosuria, amino aciduria, phosphaturia, and uric aciduria. Overflow proteinuria is caused by other systemic diseases (e.g. myeloma, intravascular hemolysis, etc.) that increase the concentration of certain proteins in the blood (e.g. Benzo’s protein, hemoglobin, etc.) beyond the absorption threshold of the kidneys, so that these proteins “overflow” from the urine. Secretory proteinuria consists of secretory mucin (e.g., increased secretion of inflammatory stimuli in the ascending branches of the medullary collaterals) or IgA (e.g., tubulointerstitial lesions in the kidney). Tissue proteinuria is seen in various enzymes and proteins released after tissue destruction, etc. These substances have small molecular weights and are excreted from the urine if the content exceeds the reabsorption threshold of the renal tubules. 4.What is the significance of observing the morphology of red blood cells in urine The observation of the morphology of red blood cells in urine can provide clues to the origin of red blood cells, thus helping to obtain a diagnosis of the cause of hematuria. The morphology of red blood cells in urine can be observed by applying phase contrast microscopy, and the specimen should be collected from fresh urine. If the red blood cell morphology is uniform in size and remains mostly normal in morphology, it is usually of subglomerular origin. If the erythrocytes originate from the glomerulus and above, the erythrocytes vary in size, shades of color, and morphology due to mechanical damage to the glomerular filtration barrier during the process of passing through the glomerulus to become urine, deformation due to extrusion and other effects when passing through the renal tubules, physical damage such as complex osmotic pressure changes in the renal tubules, and chemical damage to the cell contents released from the broken erythrocytes The red blood cells can be crumpled, ruptured, defective or budding, etc., as well as abnormal distribution of hemoglobin within the red blood cells. 5, what is leukocyte urine normal adult clean middle urine after centrifugation microscopic examination, leukocytes should be less than 5 / high magnification field or less than 70,000 leukocytes per hour excretion male, female less than 140,000. If the urine contains a high number of leukocytes and/or pus cells it is called leukocyturia. The test is performed by centrifugation of 10 ml of intermediate urine at 1,500 rpm for 5 minutes and retention of the urine sediment for microscopic examination, which can be identified as leukocyturia if there are more than 5 leukocytes per high magnification field. However, the first step in the diagnosis of leukocyturia is to determine that the leukocytes are from the urinary system and not due to contamination from genital secretions (e.g., leukorrhea). In addition to leukocytes, a large number of flattened epithelial cells can be seen in addition to leukocytes in the case of leukocyte contamination. The most common cause of leukocyturia is an infectious disease of the urinary tract, but non-infectious diseases of the urinary tract and infectious diseases of the tissues adjacent to the urinary tract can also cause leukocyturia. Leukocyturia with irritating symptoms such as urinary frequency, urgency and painful urination often indicates the presence of a specific or non-specific urinary tract infection and should be promptly examined for urinary bacteria. If a non-specific infection is confirmed, further differentiation should be made between upper or lower urinary tract infections. If the finding is a non-specific infection with negative bacterial culture and leukocyturia that is not treated with antibiotics, attention should be paid to the presence of specific infections such as tuberculosis.